1. Field of the Invention
The invention relates to multiple input multiple output (MIMO) antennas, and particularly to a MIMO antenna for use in ultra-wideband (UWB) communication systems.
2. Description of Related Art
A frequency band of an UWB wireless communication system is 3.1-10.6 GHz. In a wireless communication system, the antenna is a key element for radiating and receiving radio frequency signals. Therefore, an operating frequency band of the antenna must be 3.1-10.6 GHz or greater. In wireless communications, the number of users continues to increase and data traffic is becoming an increasing more important part of the wireless communication system. Both of these factors mean that it is important for operators to look for methods of increasing the capacity of their wireless communication systems to meet future demands.
A relatively new radio communications technology known as multiple input multiple output (MIMO) systems provides for increased system capacity. A number of antennas are used on both the transmitter and receiver, which together with appropriate beam forming and signal processing technologies are capable of providing two or more orthogonal radio propagation channels between the two antennas. The antennas are spaced apart in order to decorrelate the signals associated with adjacent antennas.
There is a need for improved antenna arrangements for use with UWB MIMO systems.